Honestly? Skip the 85/1.2-L....it is a massive beast, and it has only ONE length. For outdoor portraits, I would rather have the 70-200mm f/2.8 L IS USM model either the original, or the newer Mark II variant. With the 70-200, you will still have great optics, but you will also have focal length flexibility, and focal length variation and variety. Any 85mm prime forces you to work within a fairly narrow range of distances. Many times, it's more comfortable for subjects if the photographer is not "breathing down their necks"--which is what an 85mm prime can lead to many times. Moving BACK, and using focal length, gives subjects more "space", and you are NOT INSIDE of their "personal space". This can be very helpful, as you direct the mom and daughter to interact with one another, and you capture the shots from just outside of their "space bubble".
I'm not that keen on the 24-70 lens because of the working distances it imposes. The bottom end of the zoom range is very dubious.